Hot water is an essential commodity in the modern world, and a water heating system is an appliance commonly used in households throughout the world.
Energy consuming heating water systems are prevalent today; however, many of them cause a significant waste of energy since typically there is no way of knowing the amount of hot water present in the water tank, and all the water in the tank is heated even though a small amount is needed.
In some countries, where energy is relatively expensive, solar energy is used for heating the water. However, the solar energy cannot generally provide hot water 24 hours a day, 365 days a year, and therefore complementary heating involving energy consumption is required. The source of energy for this purpose, in most cases, is electricity.
In order to save energy, it is preferable to heat only the amount of water needed. However, in water heating systems of the prior art, the user is not provided with any indication regarding the amount of hot water in the tank. Generally, this causes the user to activate the heating element of the system either longer time than necessary resulting in a waste of energy, or shorter time than necessary, resulting in a colder and insufficient amount of water than desired. Furthermore, in some of the cases even after the water heating is presumably completed, the user has no indication of the amount of hot water in the tank or its temperature, and must open the tap and wait a relatively long time for regulating the temperature, resulting in a waste of water and time.
The lack of accurate capacity indication of the hot water in the tank causes inconvenience and waste of energy, water and time. In cases wherein the user constantly activates the water heating throughout the day and night, there is even more energy waste, as the user usually over heats the water in the tank. This energy waste is added to the energy loss resulting from the temperature difference between environment and the water in the tank, which in many cases is significant.
Of course there are times when a user requires a relatively larger amount of hot water than in other times. In the systems of the prior art, the pre-planning of the hot water capacity is either unavailable, or unsatisfactory. In conventional water heating systems of the prior art, and particularly for safety purposes, there is a thermostat mounted in a pocket at the bottom of the water tank, which senses the water temperature, and disconnects the electrical supply when a pre-assigned maximum temperature is reached. However, in this case, the regular user does not have access to the thermostat, and does not have control over the pre-assigned disconnecting maximum temperature.
Another drawback of prior art conventional water heating systems is their inability to asses past temperature data of the water heating in the tank, as in many cases this past data can allow a better and more accurate assessment of the average water temperature within the tank or the amount of warm water within the tank. This is particularly due to the fact that the heat distribution within the tank varies in various conditions, and due to the fact that the temperature reading by a single temperature sensor (as is usually used) cannot account for this heat distribution, and for the various distributions of heat during various conditions. For example, there are times in which the water is heated by an electrical power. There are other times in which the water is heated by solar energy, and still other times in which the water is heated both by solar energy and electrical power. Still in other times, water is drained during some type of heating (solar or electrical), and other times in which water is drained during non-heating periods. In any case a system is needed that can process data temperatures of the water in the boiler, taking into account all these possible conditions and accurately assess the average water temperature within the tank, or the amount of heat within the tank.
U.S. Pat. No. 6,002,114 discloses a commercial heating system having four electric heating elements, and a plurality of sensors. The heating elements are activated according to water temperature at the inlet and outlet of the tank, while further considering the inlet water flow rate. Nevertheless, this publication requires a plurality of sensors and it lacks disclosure of a system for heating only the desired amount of water in the tank, in order to save energy.
It is an object of the present invention to provide a water heating system which displays and indicates to the user the amount of hot water in the tank.
It is another object of the present invention to provide a system which allows a user to determine the amount of hot water he needs in a domestic water heating system.
It is still another object of the present invention to provide a domestic water heating system which is capable of assessing the average temperature of the water in the tank based on past temperature readings, and to display the same to the user.
It is still another object of the present invention to provide a system which allows the user to check the efficiency of his water heating system.
Other objects and advantages of the invention will become apparent as the description proceeds.